London mosque link to Beslan

A member of the group responsible for the Beslan school massacre last month is a British citizen who attended the infamous Finsbury Park mosque in north London, The Observer can reveal.

Two other members of the group, loyal to Chechen warlord Shamil Basayev, are also believed to have been active in the UK until less than three years ago. They are suspected of taking part in the raid on the school in which 300 people, half of them children, died.

Russian security sources described Kamel Rabat Bouralha, 46 years old and the oldest of the three, as a 'key aide' of Basayev, who has a £5.5 million price on his head. Basayev has boasted of training the men who took control of the school and wired it with explosives. Investigators believe that the three men, all Algerian-born, travelled to Chechnya from London to take part in fighting there in 2001.

Russian investigators are thought to have now identified most of the 33 men who occupied the school in Beslan last month. They include two Algerians in their mid-30s called Osman Larussi and Yacine Benalia. Both are thought to have been based in London until recently. Like Bouralha, they too are believed to have attended Finsbury Park mosque and to have joined the network of groups loyal to Basayev on arrival in Chechnya.

General Ilya Shabalkin said that Bouralha had been detained while attempting to leave Russia for medical treatment in Azerbaijan. 'He says he is innocent, but there is strong evidence of his involvement in a grave crime,' Shabalkin said.

Senior sources at Scotland Yard are investigating the Russian information. Former associates in London confirmed that Bouralha had been a frequent visitor at Finsbury Park mosque from around 2000.

According to Russian security sources, there are up to 300 Arab mercenaries operating with rebel formations in Chechnya. However, Moscow has been keen to exaggerate 'foreign' elements among Chechen militants, often blaming 'al-Qaeda' despite little evidence to suggest the group's involvement. Recently some analysts have tried to establish links between Chechen militants and Abu Musab al-Zarqawi's al-Tauhid group, which is holding Ken Bigley hostage in Iraq.

The Observer has obtained detailed reports into al-Zarqawi's group compiled largely from 'communications intercepts' by a Western intelligence service. A series of telephones seized from militants has allowed investigators to build up a picture of a European network that stretches from Poland to the UK. There are several references to obtaining false documents from London.